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A permissive vaccine prevents disease in the immunized host, but does not block virus infection. Would a permissive vaccine lead to the emergence of more virulent viruses?
This hypothesis is based on the notion that viruses which kill their hosts too quickly are not efficiently transmitted, and are therefore removed by ...

Foot-and-mouth disease virus (FMDV) infects cloven-hoofed animals such as cattle, pigs, sheep, goats, and many wild species. The disease caused by this virus is a substantial problem for farmers because infected animals cannot be sold. Transgenic pigs have now been produced which express a short interfering RNA (siRNA) and consequently ...

Although we now understand that viruses are the most abundant organisms on Earth, there are gaps in our knowledge about their distribution in different environments. Results of a new study reveal the diversity and distribution of viruses in Arctic fresh waters.

Patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) showed clinical improvement after extended treatment with the anti-B-cell monoclonal antibody rituximab. This result suggests that in a subset of patients, ME/CFS might be an autoimmune disease.

Back in 2013 I built a Wall of Polio in my laboratory – a large stack of six-well cell culture plates that have been used to measure the concentration of polioviruses in various samples by plaque assay. It became a focal point of the lab at which many guests came ...

Chronic wasting disease is a prion disease of cervids (deer, elk, moose) that is potentially a threat to human health. A role for environmental prion contamination in transmission is supported by the finding that plants can take up prions from the soil and transmit them to animals.

Virologist Richard Elliott passed away on 5 June 2015. I have known Richard since 1979 and I would like to provide some personal recollections of this outstanding virologist. A summary of his work can be found at the MRC-University of Glasgow Centre for Virus Research science blog.

The thousands of survivors of the Ebolavirus outbreak in western Africa – more than at any other time – are fortunate to have survived the disease. However, their health problems are not behind them. A new study shows that the survivors of Ebolavirus have long-term sequelae more than 2 years ...

Did you ever wonder what different virus infections you have had in your lifetime? Now you can find out with just a drop of your blood and about $25.
Immune defense systems of many hosts produce antibodies in response to virus infections. These large proteins, which are generally virus specific, can ...

Many microbes live in extreme environments, encountering conditions that are very hot, very cold, highly acidic, or very salty. The viruses that infect such microbes must also be able to retain infectivity in extreme conditions. How do they do it?
Clues come from the observations that the genomes of viruses that ...

A major goal of viral oncotherapy – the use of viruses to destroy tumors – is to design viruses that kill tumor cells but not normal cells. Two adenoviruses provide perfect examples of how this specificity can be achieved.
Adenovirus CG0070, designed to treat bladder cancer, and adenovirus Oncorine, for ...

Rhinovirus is the most frequent cause of the common cold, and the virus itself is quite common: there are over 160 types, classified into 3 species. The cell receptor has just been identified for the rhinovirus C species, which can cause more severe illness than members of the A or ...

About eight percent of human DNA is viral: it consists of retroviral genomes produced by infections that occurred many years ago. These endogenous retroviruses are passed from parent to child in our DNA. Some of these viral genomes are activated for a brief time during human embryogenesis, suggesting that they ...

Virus populations do not consist of a single member with a defined nucleic acid sequence, but are dynamic distributions of nonidentical but related members called a quasispecies (illustrated at left). While next-generation sequencing methods have the capability of describing a quasispecies, the errors associated with this technology have limited progress ...

A leukemia-like cancer is killing soft-shell clams along the east coast of North America. The cancer is transmitted between animals in the ocean, and appears to have originated in a single clam as recently as 40 years ago.

The first immortal human cell line ever produced, HeLa, originated from a cervical adenocarcinoma taken from Henrietta Lacks. The cell line grew so well that it was used in many laboratories and soon was found to contaminate other cell lines. Now HeLa RNA has made its way into human sequence ...

The enzymes that make copies of the DNA or RNA genomes of viruses – nucleic acid polymerases – can be placed into two broad categories depending on whether or not they require a primer, a short piece of DNA or RNA, to get going. The structure of the primer-independent RNA ...

Viruses can be broadly classified according to whether or not the particle is enveloped – surrounded by a membrane taken from the host cell – or naked. Some naked viruses apparently are more modest than we believed.

Because viruses must bind to cell surface molecules to initiate replication, the use of soluble receptors to block virus infection has long been an attractive therapeutic option. Soluble receptors have been developed that block infection with rhinoviruses and HIV-1, but these have not been licensed due to their suboptimal potency. ...

An otherwise balanced review of selected aspects of Ebolavirus transmission falls apart when the authors hypothesize that ‘Ebola viruses have the potential to be respiratory pathogens with primary respiratory spread.’
The idea that Ebolavirus might become transmitted by the respiratory route was suggested last year by Michael Osterholm in a Times ...

The entry of enveloped viruses into cells begins when the membrane that surrounds these virus particles fuse with a cell membrane. The process of virus-cell fusion must be tightly regulated, to make sure it happens in the right cells. The fusion activity of measles viruses isolated from the brains of ...

Jason Roberts, a virologist at the Victorian Infectious Disease Reference Laboratory in Melbourne, Australia, creates three-dimensional simulations of viruses showing how the molecules that make up the capsid and genome might move in very short periods of time. I visited Jason in his laboratory at the newly constructed Peter Doherty ...

If the reader does not believe that viroids and satellites are distinctive, then surely prions, infectious agents composed only of protein, must impress.
The question of whether infectious agents exist without genomes arose with the discovery and characterization of infectious agents associated with a group of diseases called transmissible spongiform encephalopathies ...

Satellites are subviral agents that differ from viroids because they depend on the presence of a helper virus for their propagation. Satellite viruses are particles that contain nucleic acid genomes encoding a structural protein that encapsidates the satellite genome. Satellite RNAs do not encode capsid protein, but are packaged by ...

We all know about selfies, made popular by the camera in our cell phone. Well, here is the *real* deal - the 'cell-fie'. It's a photograph of my cell culture incubator full of stacks of plates in which HeLa cells are growing - and it's complete with my reflection.

Genomes of non-defective viruses range in size from 2,400,000 bp of dsDNA (Pandoravirus salinus) to 1,759 bp of ssDNA (porcine circovirus). Are even smaller viral genomes possible? The subviral agents called viroids provide an answer to this question.
Viroids, the smallest known pathogens, are naked, circular, single-stranded RNA molecules that do ...

The polio eradication and endgame strategic plan announced by the World Health Organization in 2014 includes at least one dose of inactivated poliovirus vaccine (IPV). Since 1988, when WHO announced the polio eradication plan, it had relied exclusively on the use of oral poliovirus vaccine (OPV). The rationale for including ...

Human influenza viruses replicate almost exclusively in the respiratory tract, yet infected individuals may also have gastrointestinal symptoms such as vomiting and diarrhea. In mice, intestinal injury occurs in the absence of viral replication, and is a consequence of viral depletion of the gut microbiota.

Recovering viral genomes from ancient specimens can provide information about viral evolution, but not many old nucleic acids have been identified. A study of 700 year old caribou feces reveals that viruses can be protected for long periods of time – under the right conditions.

Sea stars are lovely marine invertebrates with a round central body connected to multiple radiating legs (photo credit). In the past year millions of sea stars in the west coast waters of North America have melted into piles of slime and ossicles. Sea star associated densovirus might be the cause ...

After the governors of New York and New Jersey decided that health workers who have returned from the Ebola virus outbreak in West Africa should be subject to a 21-day quarantine, two Nobel laureates entered the fray. Bruce Beutler feels that the quarantine is the right thing to do, while ...

I have received many questions about whether immunizing with Reston virus could protect against infection with Ebola virus. Usually the question comes together with the statement ‘because Reston virus does not cause disease in humans’. I can think of two reasons why a Reston virus vaccine is not a good ...

The Liberian man who was diagnosed with Ebola virus infection after traveling to Dallas, Texas, was treated with an antiviral drug called brincidofovir. This drug had originally been developed to treat infections with DNA-containing viruses. Why was it used to treat an Ebola virus infection?

The time before the symptoms of a viral infection appear is called the incubation period. During this time, viral genomes are replicating and the host is responding, producing cytokines such as interferon that can have global effects, leading to the classical symptoms of an acute infection (e.g., fever, malaise, aches, ...

In February 2014 I wrote about children in California who developed a poliomyelitis-like paralysis, also called acute flaccid paralysis or AFP. However, the cause of this paralysis was not known. The CDC has released its study of these cases and concludes “The etiology of AFP with anterior myelitis in the ...

Given the extent of the Ebola virus outbreak in West Africa, transport of an infected individual to the US was bound to happen. The case is an adult who had contact with an Ebola virus-infected woman in Liberia, then traveled to Dallas. He had no symptoms before arriving in the ...

As the West African epidemic of Ebola virus grows, so does misinformation about the virus, particularly how it is transmitted from person to person. Ebola virus is transmitted from human to human by close contact with infected patients and virus-containing body fluids. It does not spread among humans by respiratory ...

In a recent New York Times OpEd entitled What We’re Afraid to Say About Ebola, Michaeal Osterholm wonders whether Ebola virus could go airborne:
You can now get Ebola only through direct contact with bodily fluids. If certain mutations occurred, it would mean that just breathing would put one at risk ...

During the winter of 1962 in California, a new virus was isolated from the oropharynx of 4 children who had been hospitalized with respiratory disease that included pneumonia and bronchiolitis. On the basis of its physical, chemical, and biological properties, the virus was classified as an enterovirus in the picornavirus ...

Antigenic variation is a hallmark of influenza virus that allows the virus to evade host defenses. Consequently influenza vaccines need to be reformulated frequently to keep up with changing viruses. In contrast, antigenic variation is not a hallmark of poliovirus – the same poliovirus vaccines have been used for nearly ...

Many people have a new awareness of the disease known as amyotrophic lateral sclerosis, or ALS, thanks to the Ice Bucket Challenge initiated by the ALS Association. Fewer might know that retroviruses have been proposed to play a role in the development of the disease.

Dr. Tom Solomon is Director of the Institute for Infection and Global Health at the University of Liverpool. In this video he speaks with Vincent Racaniello about the 2014 outbreak of Zaire ebolavirus in West Africa. Dr. Solomon discusses why the epidemic has spread, how it might be curtailed, the ...

Scientists for Science are confident that biomedical research on potentially dangerous pathogens can be performed safely and is essential for a comprehensive understanding of microbial disease pathogenesis, prevention and treatment. The results of such research are often unanticipated and accrue over time; therefore, risk-benefit analyses are difficult to assess accurately.
If ...

Experiments with the most dangerous human viruses, such as Ebola virus and Lassa virus, are carried out in biosafety level 4 (BSL-4) laboratories. Since visiting the Northeast Infectious Diseases Laboratory BSL-4 and releasing the documentary video Threading the NEIDL, I was given the opportunity to tour three BSL-4 laboratories in ...

Wild poliovirus has been detected in the sewers of Brazil and Israel. Fortunately, no cases of poliomyelitis have been reported in either country. Why is poliovirus present in these countries and what are the implications for the eradication effort?
Wild type poliovirus (e.g. not vaccine-derived virus) was detected in sewage samples ...

Segmented genomes abound in the RNA virus world. They are found in virus particles from different families, and can be double stranded (Reoviridae) or single stranded of (+) (Closteroviridae) or (-) (Orthomyxoviridae) polarity. Our recent discussion of the advantages of a segmented viral genome, compared with monopartitie genomes, generated a ...

Ten years ago this month I wrote the first post at virology blog, entitled Are viruses living? Thanks to EE Giorgi for pointing out the ten year anniversary, and also for publishing an interview with me at her blog, Chimeras. Here is how this blog got started.

Evolution proceeds by selection of mutants that arise by error-prone duplication of nucleic acid genomes. It is believed that mutations that are selected in a gene are dependent on those that have preceded them, an effect known as epistasis. Analysis of a sequence of changes in the influenza virus nucleoprotein ...

A recent study by scientists at the Ludwig Center for Cancer Immunotherapy offers a new, multifaceted therapy for destroying tumors. A team of researchers led by Dmitriy Zamarin combined checkpoint blockade, a technique aimed at enhancing antitumor immune responses, with oncolytic viral therapy, a technique that uses viruses to kill ...

Later this month (May 2014) the World Health Assembly will decide whether to destroy the remaining stocks of variola virus – the agent of smallpox – or to allow continued research on the virus at WHO-approved laboratories. We are interested in your opinion on this issue. Please follow the link ...

The 1918 influenza pandemic was particularly lethal, not only for the very young and the very old (as observed for typical influenza), but unexpectedly also for young adults, 20 to 40 years of age (pictured). It has been suggested that the increased lethality in young adults occurred because they lacked ...

This week’s virology question comes from Eric, who writes:
I’m working on an MPH and in one of my classes we are currently studying the influenza virus. I’d forgotten that the genome is in 8 separate parts. Curious, I’ve been searching but can’t find any information as to why that is?
What ...

On the science show This Week in Virology we receive many questions and comments, which are read every week. I also get many questions here on virology blog, which I tend to answer by email. However I think that everyone could benefit from these questions, so I’ve decided to post ...

About eight percent of human DNA is viral – remnants of ancestral infections with retroviruses. These endogenous retroviral sequences do not produce infectious viruses, and most are considered to be junk DNA. But some of them provide important functions. The protein called syncytin, which is essential for formation of the ...

Six new cases of Heartland virus disease have been identified in residents of Missouri and Tennessee. The cause of this disease appears to be a member of the Phlebovirus genus in the Bunyaviridae family that was first identified in 2009 and appears to be transmitted by the Lone Star tick ...

In the spring of each year I teach a virology course to undergraduates and masters students at Columbia University. I produce video recordings of all my lectures not only for students in the course, but for anyone else who is interested in learning about viruses.
You can find my virology lectures ...

Because all animal viruses initiate infection by binding to a receptor on the cell surface, this step has long been considered a prime target for antiviral therapy. Unfortunately, drugs that block virus attachment to cells have never shown much promise. Another approach, which is to ablate the receptor from the ...

Infection with influenza virus is known to increase susceptibility to bacterial infections of the respiratory tract. In a mouse model of influenza, increased bacterial colonization was also observed after administration of an infectious, attenuated influenza virus vaccine. Primary influenza virus infection increases colonization of the human upper and lower respiratory ...

A new virus called Pithovirus sibericum has been isolated from 30,000 year old Siberian permafrost. It is the oldest DNA virus of eukaryotes ever isolated, showing that viruses can retain infectivity in nature for very long periods of time.

Recently a number of children in California have developed a poliomyelitis-like paralysis. The cause of this paralysis is not yet known, and information about the outbreak is scarce. However, acute-flaccid paralysis is not uncommon (California would be expected to report about 75 cases a year, based on its population). The ...

There are many elements that go into making a great lecture, but the most important one is to lose the notes. If you are giving lectures in a course at any level, the worst practice you can engage in is to rely on notes. This behavior is problematic for several ...

To the collection of avian influenza viruses known to sporadically infect humans – H5N1, H7N9, H7N2, H7N3, H7N7, H9N2, and H10N7 – we can now add H10N8, recently found in two individuals in China. Avian influenza virus H10N8 was first detected in tracheal aspirates from a 73 year old woman ...

Virulence, the capacity to cause disease, varies markedly among viruses. Some viruses cause lethal disease while others do not. For example, nearly all humans infected with rabies virus develop a disease of the central nervous system which ultimately leads to death. In contrast, most humans are infected with circoviruses with ...

Three years ago today, on 13 January 2011, the last case of poliomyelitis was reported in India. This achievement represents a remarkable turnaround for a country where control of the disease had for years been extremely difficult. As recently as 2009 there were 741 confirmed cases of polio caused by ...

Middle Eastern respiratory syndrome coronavirus (MERS-CoV), first identified in the fall of 2012 in a Saudi Arabian patient, has since infected over 160 individuals, causing 71 deaths. Identifying the source of infection is important for efforts to prevent further infections. Recently two studies revealed the presence of antibodies to the ...

If you are looking for the perfect present for that infectious person in your life, there are many microbe-themed possibilities. Here are some suggestions, from t-shirts, to watercolors, glass sculptures, and paper to wrap it in.

The hemagglutinin (HA) and neuraminidase (NA) glycoproteins of the influenza virus particle serve distinct functions during infection. The HA binds sialic acid-containing cellular receptors and mediates fusion of the viral and cell membranes, while the NA removes sialic acids from glycoproteins. Apparently this division of labor is not absolute: influenza ...

It is well known that aquatic birds are a major reservoir of influenza A viruses, and that pandemic human influenza virus strains of the past century derive viral genes from this pool. The recent discovery of two new influenza A viruses in bats suggests that this species may constitute another ...

The influenza virus particle is made up of the viral RNA genome wrapped in a lipid membrane (illustrated). The membrane, or envelope, contains three different kinds of viral proteins. The hemagglutinin molecule (HA, blue) attaches to cell receptors and initiates the process of virus entry into cells. I have written ...

The SARS pandemic of 2002-2003 is believed to have been caused by a bat coronavirus (CoV) that first infected a civet and then was passed on to humans. The isolation of a new SARS-like coronavirus from bats suggests that the virus could have directly infected humans.

Neisseria meningitidis may cause septicemia (bacteria in the blood) and meningitis (infection of the membrane surrounding the brain), but the bacterium colonizes the nasopharynx in 10-20% of the human population without causing disease. Although understanding how the bacterium changes from a commensal to a pathogen has been elusive, an important ...

As a virologist who has worked on poliovirus since 1979, I would be remiss if I did not note that today, 24 October, is World Polio Day. World Polio Day was established by Rotary International over a decade ago to commemorate the birth of Jonas Salk, who led the first ...

Hepatitis B virus (HBV, illustrated) is a substantial human pathogen. WHO estimates that there are now 240,000,000 individuals chronically infected with HBV worldwide, of which 25% will die from chronic liver disease or hepatocellular carcinoma. The hepatitis B virus vaccine is highly effective at preventing infection. Because there are no ...

We have been using HeLa cells in my laboratory since 1982, when I arrived at Columbia University Medical Center fresh from postdoctoral work with David Baltimore at MIT. I brought with me a line of HeLa cells and used them for 30 years for our research on viruses. Here is ...

When virologists Fouchier and Kawaoka were isolating avian influenza H5N1 viruses that could transmit among ferrets by aerosol, there was consternation from some quarters that such viruses might escape from the laboratory and cause a pandemic in humans. Part of the fear came from the fact that the case fatality ...

Readers of this blog will remember the furor sparked by Fouchier’s experiments in 2011 in which he developed an avian influenza H5N1 isolate that could transmit among ferrets by aerosol. When Fouchier was ready to publish the results, the Dutch government required that Fouchier apply for an export license. In ...

Do you remember the retrovirus XMRV, initially implicated as the cause of chronic fatigue syndrome, and later shown to be a murine virus that contaminated human cells grown in mice? Another virus thought to be associated with human disease has recently been shown to be a contaminant, derived from a ...

When you purchase chicken eggs at the market, they usually have white or brown shells. But some breeds of chicken produce blue or green eggs. The blue color is caused by insertion of a retrovirus into the chicken genome, which activates a gene involved in the production of blue eggs.

How many different viruses are there on planet Earth? Twenty years ago Stephen Morse suggested that there were about one million viruses of vertebrates (he arrived at this calculation by assuming ~20 different viruses in each of the 50,000 vertebrates on the planet). The results of a new study suggest ...

Reticuloendotheliosis viruses (REVs) are retroviruses that cause a rare disease of gamebirds and waterfowl that includes anemia, immunosuppression, neoplasia, runting, and abnormal feathering. Since the first isolation of REV from a turkey in 1957, REVs were believed to be strictly avian viruses. It now appears that REVs are mammalian viruses ...

What is wrong with this paragraph from today’s New York Times that describes the origin of the Middle East Respiratory Syndrome (MERS) coronavirus:
Health officials confirmed Wednesday that bats in Saudi Arabia were the source of the mysterious virus that has sickened 96 people in the Middle East, killing 47 of ...

A group of virologists lead by Yoshihiro Kawaoka and Ron Fouchier have sent a letter to Nature and Science outlining the experiments they propose to carry out with influenza H7N9 virus. Avian influenza H7N9 virus has caused over 130 human infections in China with 43 fatalities. The source of the ...

The discovery of the giant Mimivirus and Megavirus amazed virologists (and also many others). Their virions (750 nanometers) and DNA genomes (1,259,000 base pairs) were the biggest ever discovered, shattering the notions that viruses could not be seen with a light microscope, and that viral genomes were smaller bacterial genomes. ...

Poliovirus has been found in sewage in Israel. The virus detected is not vaccine-derived poliovirus; it is wild-type 1 poliovirus, the strain that occurs naturally in the wild and which the World Health Organization is trying very hard to eradicate from the planet.

Viruses are obligate intracellular parasites: they must enter a cell to reproduce. To gain access to the cell interior, a virus must first bind to one or more specific receptor molecules on the cell surface. Cell receptors for viruses do not exist only to serve viruses: they also have cellular ...

An outbreak of hepatitis A virus (HAV) infections in eight US states has been attributed to consumption of Townsend Farms Organic Anti-Oxidant Blend frozen berry and pomegranate mix purchased from Costco markets. Since March 2013, 118 individuals have acquired the infection and 80% report having eaten this fruit product. Townsend ...

The Polio Wall of Fame is a set of fifteen sculptured busts of 17 individuals who made important contributions to understanding and preventing poliomyelitis. The busts are mounted on an exterior wall of Founder’s Hall at the Roosevelt Warm Springs Institute for Rehabilitation in Warm Springs, Georgia, USA. In my ...

Two back-to-back papers were published last week that provide a detailed analysis of what it would take for avian influenza H5N1 and H7N9 viruses to switch to human receptors. A single amino acid change in the viral hemagglutinin protein is sufficient to quantitatively change binding of the virus from avian ...

For fours years I have taught a virology course at Columbia University and have posted videos of each lecture on my website, virology.ws, and at iTunes University. Nearly 100,000 individuals have subscribed to my virology course at iTunes University. Now Columbia has signed an agreement with Coursera, and on 1August, ...

Miravirsen is a drug that binds to and blocks the function of a cellular microRNA called miR-122 that is required for the replication of hepatitis C virus (HCV). Treatment of chimpanzees chronically infected with HCV with this drug leads to suppression of viral replication. The results of a phase 2b ...

There have been 131 confirmed human infections with avian influenza H7N9 virus in China, but so far there is little evidence for human to human transmission. Three out of four patients report exposure to animals, ‘mostly chickens‘, suggesting that most of the infections are zoonoses. Whether or not the virus ...

There was much written concerning the research published earlier this month in Science, where researchers from China’s Harbin Veterinary Research Institute reported creating an avian H5N1 (highly pathogenic) and pandemic 2009 H1N1 (easily transmissible) hybrid, that according to them, achieved airborne spread between guinea pigs. Included in the ...

Those of you with an interest in virology, or perhaps simply sensationalism, have probably seen the recent headlines proclaiming another laboratory-made killer influenza virus. From The Independent: ‘Appalling irresponsibility: Senior scientists attack Chinese researchers for creating new strains of influenza virus’; and from InSing.com: ‘Made-in-China killer flu virus’. It’s unfortunate ...

I joined Buddhini Samarasinghe and Scott Lewis on a Science Sunday Hangout on Air to talk about my career in virology: how I came to be interested in viruses, and what goes on in my laboratory. You can find hangouts and more at the ScienceSunday community.
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Virologist Hilary Koprowski died on 11 April 2013 at the age of 96. His main accomplishments are nicely summarized in the New York Times, but for a more comprehensive overview of his life, I highly recommend his biography Listen to the Music by Roger Vaughan. I did not have many ...

During my visit to Berkeley, CA to record TWiV #228, I met Deb Sklut, an artist who is inspired by the power of science. I recorded a brief conversation with Deb which you can view below. Her work can be found at SqueakySqueegeeArt.etsy.com.

An outbreak of high-pathogenicity avian influenza H7N7 virus that took place on 255 poultry farms in the Netherlands during 2003 has been used to provide clues about the current avian influenza H7N9 viruses in China. During the Dutch outbreak 453 humans showed symptoms of illness and 89 were confirmed to ...

There have been over 60 human infections with avian influenza virus H7N9 in China, and cases have been detected outside of Shanghai, including Beijing, Zhejiang, Henan, and Anhui Provinces. Information on the first three cases has now been published, allowing a more detailed consideration of the properties of the viral ...

Earlier this month the European Molecular Biology Laboratory (EMBL) published the DNA sequence of the genome of HeLa cells, the cell line that is widely used for research in virology, cell biology, and many other areas. This cell line was produced from a tumor taken from Henrietta Lacks in 1951. ...

Recently thousands of dead and decaying pigs were pulled from rivers in Shanghai and Jiaxing, China. Apparently farmers dumped the animals into the water after the pigs became ill, and porcine circovirus was subsequently detected in the in pig carcasses and in the water. Porcine circoviruses are small, icosahedral viruses ...

Viruses are obligate intracellular parasites, which means that they must enter a cell to reproduce. As virions are too large to diffuse passively across the plasma membrane, cellular pathways for uptake of extracellular materials provide entry routes. The first step in entry is adherence of virus particles to the membrane, ...

Each year as I teach my undergraduate virology course, I record each lecture and put them online where they are freely accessible. A student in my virology course approached me recently to thank me for making the lectures available online, and wondered why other professors did not so the same. ...

The US Office of Science and Technology Policy recently released proposed guidelines for maximizing the benefits and minimizing misuse of life sciences research. The measures establish oversight responsibilities for universities and other institutions that receive Federal funding.

The risk of being infected with human immunodeficiency virus type 1 (HIV-1) is substantially enhanced in individuals with other sexually transmitted diseases. For example, infection with herpes simplex virus type 2 (HSV-2) increases the risk ratio of acquiring HIV from 2 to 4. Explanations for this increased risk include direct ...

Harvard University is home to some of the world’s finest virologists. But apparently they do not communicate with the writers at Harvard Magazine, where a botched story on the avian H5N1 influenza virus has just been published.

About 2% of the world’s population is chronically infected with hepatitis C virus (HCV). This enveloped, positive-strand RNA virus was discovered in 1989, but serological and phylogenetic evidence indicates that it has been infecting humans for hundreds of years, perhaps as long ago as the 14th century. All human viral ...

The lethality of avian influenza H5N1 infections in humans has been a matter of extensive debate. The >50% case fatality rate established by WHO is high, but the lethality of the virus might be lower if there are many infections accompanied by mild or no disease. One way to answer ...

The spring semester has begun at Columbia University, which means that it is time to teach my virology course. The fourth annual installment of my virology course, Biology W3310, has begun. This course, which I taught for the first time in 2009, is intended for advanced undergraduates and convenes at ...

Both Nature and the New York Times have weighed in on the resumption of influenza H5N1 research. In an editorial from 23 January 2013, Nature opines that “Experiments that make deadly pathogens more dangerous demand the utmost scrutiny”. They call for a quantitative risk-benefit analysis of H5N1 research. I don't ...

In early 2012 influenza virus researchers around the world decided to stop working on highly pathogenic avian influenza H5N1 virus. This decision came after work from the Fouchier and Kawaoka laboratories revealed the isolation of influenza H5N1 strains that can be passed among ferrets by aerosol. The moratorium on influenza ...

Poliovirus recently made the cover of Time magazine. Prompted by a reader question, I searched the Time archive to find out if there have been other virology-themed covers. I found fifteen in all, depicting poliovirus (3), herpesvirus (1), HIV/AIDS (4), influenza (5), and SARS coronavirus (2) (I did not distinguish ...

The Centers for Disease Control and Prevention has released early estimates of the effectiveness of this season’s influenza vaccine in preventing influenza infection. Estimated vaccine effectiveness is 62%. But even if you get infected after immunization, you are likely to have reduced illness, antibiotic use, doctor visits, time lost from ...

During my visit to the University of Vermont today I had lunch with seven talented Microbiology Ph.D. students. One of them asked me what was an important quality to have for achieving success in science. I said without hesitation, ‘Be curious’. It’s the answer I always give. Being curious is ...

Poliovirus has made the cover of Time magazine. The Time cover image for the 14 January 2013 issue is a model of poliovirus bound to a soluble form of its cellular receptor, CD155. I was part of the team that solved the structure of this complex in 2000, together with ...

Yesterday many US newspapers carried front-page stories on the severity of influenza so far this season. The New York Times story began with “It is not your imagination — more people you know are sick this winter, even people who have had flu shots.” Is this really a bad flu ...

Deans of public health schools in the United States have sent a letter to President Obama, in which they criticize the use of a vaccination campaign by the Central Intelligence Agency in Pakistan to hunt for Osama bin Laden. I wonder if he will reply.

The World Health Organization’s campaign to eradicate poliomyelitis made impressive inroads in 2012: only 212 cases were reported, compared with 620 the previous year; moreover, India remained polio-free. The dark side of this story is that as wild polio is eliminated, vaccine-associated poliomyelitis moves in to take its place. The ...

If you were a science professor, and you received two equally strong applications for the position of laboratory manager, one from a female, one from a male, which one would you pick? The answer might surprise you.

An outbreak of ten cases of poliomyelitis caused by circulating vaccine-derivied poliovirus type 2 (cVDPV2) is ongoing in Pakistan, centered in the Kila Abdulla/Pishin area of Baluchistan. The same virus strain has spread to the neighboring Kandahar province in Afghanistan, where two paralytic cases have been reported. Vaccine-derived poliomyelitis is ...

The Centers for Disease Control and Prevention has released its latest estimates on the number of new HIV infections in the United States. HIV remains a serious health problem, with an estimated 47,500 people becoming newly infected with the virus in the United States in 2010. About 12,000 youth were ...

Maryn McKenna summarizes what we know about the murder of six people working as polio vaccinators who were targeted in three separate coordinated attacks in Pakistan. This comes in the wake of the CIA ruse in 2011 who used an immunization campaign to find Osama Bin Laden.

Head of the US National Institutes of Health Francis Collins was asked some tough questions by a House of Representatives subcommittee examining the new National Center for Advancing Translational Sciences, NCATS. The goal of the new center, opened in 2012, is to reduce the amount of time needed to develop ...

I am always looking for microbe-themed art; I keep a list of my findings at Microbe Art. I’ve just discovered a new artist: Jane Hartman of Trilobite Glassworks. From her website: Trilobite Glassworks features stained glass and fused glass decorative as well as functional pieces all designed and made by ...

December 2-5 is National Influenza Vaccination Week in the US. This year the push to immunize against flu comes as the disease has begun to increase substantially throughout the United States. A substantial rise in the number of influenza cases typically does not occur until the end of December ...

The Great Ape Protection and Cost Savings Act (S 810), which would prohibit the use of chimpanzees in medical research, may be voted on in the Senate this week (it was approved by a Senate committee in July). The purpose of this act is to phase out invasive research on ...

I was scheduled to deliver a lecture on picornaviruses to a virology class at Yale University this week, but had to cancel at the last minute. I prepared this screencast to make up for my absence.
The Picornaviridae is a family of non-enveloped, positive-strand RNA viruses which contains some well known ...

Many protozoan parasites (Trichomonas, Leishmania, Giardia, Plasmodium, Entamoeba, Nagleria, Eimeria, Cryptosporidium) are infected with viruses. These viruses do not infect vertebrates, but their double-stranded RNA genomes are sensed by the innate immune system, leading to inflammatory complications of protozoan infections.

Today, 24 October 2012, is World Polio Day:
World Polio Day (October 24) was established by Rotary International over a decade ago to commemorate the birth of Jonas Salk, who led the first team to develop a vaccine against poliomyelitis. Use of this inactivated poliovirus vaccine and subsequent widespread use of ...

Every different life form on earth can probably be infected with at least one type of virus, if not many more. Most of these viruses have not yet been discovered: just over 2,000 viral species are recognized. While the majority of the known viruses infect bacteria and eukaryotes, there are ...

The genomes of most higher organisms contain sequences from retroviral genomes called endogenous retroviruses (ERVs). These are DNA copies of retroviral RNAs that are integrated into the germ line DNA of the host, and passed from parent to offspring. In most species the infections that lead to germ line ERVs ...

There is no evidence for further spread among humans of a novel coronavirus recently isolated from two individuals with severe respiratory illness. This conclusion has been drawn after scrutinizing the travels (figure) and contacts of a Qatari adult who was transferred to intensive care in London.

We recorded This Week in Virology #202 at the University of Nebraska in Lincoln, Nebraska on 5 October 2012, as part of the 12th Annual Symposium in Virology. Terence Dermody, Shou-Wei Ding, Grant McFadden and I spoke about our research, and then we recorded TWiV with University of Nebraska virologists ...

Hemorrhagic fevers are among the most graphic viral diseases, inspiring movies, novels, and a general fear of infection. They are characterized by an abrupt onset and a striking clinical course involving bleeding from the nose and mouth, vomiting with blood, and bloody diarrhea. The most famous hemorrhagic fevers are produced ...

A new coronavirus has been isolated from two individuals with severe respiratory illness. It is different from the SARS coronavirus, but health officials are nonetheless preparing for a rapid response should the virus be detected elsewhere.

We celebrated the 200th episode of TWiV by visiting the National Emerging Infectious Diseases Laboratories at Boston University Medical Center, where we met with Elke, Paul, and Ron to talk about building and working in a BSL4 facility. It was an amazing visit that will be fully documented in an ...

Thirty years ago this month I arrived in the Department of Microbiology at Columbia University’s College of Physicians and Surgeons (P&S) to start my own laboratory. Thirty is not only a multiple of ten (which we tend to celebrate), but also a long time to be at one place. It’s ...

Should you ever visit Cold Spring Harbor Laboratory on Long Island, New York, be sure to go see the food blender that was used to carry out the well known Hershey-Chase experiment. The blender is located in the Szybalski Reading Room of the Carnegie Library. After entering the front door ...

Here are photographs I took during our visit to Cold Spring Harbor Laboratory to record This Week in Microbiology #40. We roamed around campus scouting locations before deciding on the Szybalski Reading Room in the Carnegie Library. That's Ray Ortega setting up in the Szybalski Reading Room. Also in some ...

Although Avery, MacLeod, and McCarty showed in 1944 that nucleic acid was both necessary and sufficient for the transfer of bacterial genetic traits, protein was still suspected to be a critical component of viral heredity. Alfred Hershey and Martha Chase showed that this hypothesis was incorrect with a simple experiment ...

Last week I was at Cold Spring Harbor Laboratory to attend a ceremony designating the well-known laboratory on Long Island as a Milestone in Microbiology site. The purpose of this program, which is administered by the American Society for Microbiology, is to recognize institutions that have substantially advanced the science ...

When I am asked to name the most lethal human virus, I never hesitate to name rabies virus. Infection with this virus is almost invariably fatal; just three unvaccinated individuals have been known to survive. New evidence from humans in the Peruvian Amazon suggests that the virus might be less ...

If you know anything about snakes you might be familiar with snake inclusion body disease, or IBD. This transmissible and fatal disease affects snakes of a variety of species but has been best studied in boas. The name comes from the presence of large masses (inclusions) in the cytoplasm of ...

When I drafted my article for TakePart (Don’t Panic – Ebola Isn’t Heading For You), I used the term ‘ebolavirus’ throughout, but the editors changed every instance to ‘Ebola virus’. Understanding which term is correct is far more complicated than you might imagine.

An outbreak of Ebola hemorrhagic fever that began in early July 2012 has involved at least 36 individuals and 16 deaths. So far the disease has been confined to a rural region west of Kampala, the capital of Uganda. The subject of Richard Preston’s scary The Hot Zone, Ebola virus ...

We all know that virologists love to dance. But did you know that they can also perform in a rock band?
At the recently concluded 2012 meeting of the American Society for Virology in Madison, WI, seven virologists and a neurobiologist, members of the band Herpetic Legion, entertained meeting attendees with ...

I still wonder why the influenza virus H5N1 ferret transmission studies generated such fear and misunderstanding among the public, the press, and even some scientists. I still cannot fully explain what transpired, but now that the papers have been published some new clues have emerged.

The second of two papers on avian influenza H5N1 virus that caused such a furor in the past year was published today in the journal Science. I have carefully read the paper by Fouchier and colleagues, and I assure you that it does not enable the production of a deadly ...

Aaron J. Shatkin was well known for his work on reoviruses beginning in the 1960s in his laboratory at the Roche Institute of Molecular Biology in Nutley, NJ and then at Rutgers University. He was among the first to appreciate that virus particles contained many different enzymes, such as RNA ...

India has been free of polio for over one year. This is a remarkable accomplishment, considering that just 30 years ago the country recorded 200,000 cases of the disease annually, or one every three minutes. With polio endemic in two neighboring countries, Pakistan and Afghanistan, and in the more distant ...

One of two papers on avian influenza H5N1 virus that caused such a furor in the past six months was published today in the journal Nature. I have read it, and I can assure you that the results do not enable the construction of a deadly biological weapon. Instead, they ...

Nearly four months ago I stood at the front of a crowded classroom at Columbia University and began teaching the third year of my undergraduate virology course. Twice a week we discussed the basic principles of virology, including how virions are built, how they replicate, and how they cause disease. ...

A dairy cow in California is the fourth known American case of mad cow disease, which is caused by prions, infectious agents composed only of protein (the story hit the press the day after my lecture on this type of illness). Unlike viruses, prions have no nucleic acid and no ...

When my laboratory discovered the cell receptor for poliovirus in 1989, many new research directions were suddenly revealed – such as creating a mouse model for poliomyelitis. One application we did not think of was to use the receptor to screen samples of drinking water for the presence of viruses.

Influenza H5N1 virus frightens many because of the widely quoted case fatality ratio of >50%, which is based on the number of deaths among the fewer than 600 cases confirmed by the World Health Organization. Such fear is misguided, because it is likely that the fatality ratio is far lower. ...

This past February I was interviewed by the Australian Broadcasting Company on the topic of the Fouchier and Kawaoka experiments on avian influenza virus H5N1. The video, Building the Perfect Bug, has been released by Journeyman Pictures and includes interviews with S.T. Lai, Laurie Garrett, Michael Osterholm, and Ron Fouchier ...

Some viruses that infect bacteria (bacteriophages) deliver their DNA into the host cell with an amazing injection machine. The tailed bacteriophages (such as T4, illustrated) store their DNA in a capsid attached to a long tail tube that is surrounded by a sheath. At the bottom of the tube is ...

A consequence of the recent warm weather in the northeastern United States is the emergence of crocuses, an event that I documented at the TWiV Facebook page. A reader replied that it reminded her of the highly valued tulips with beautiful variegations produced by viruses.

Ron Fouchier has discussed his influenza H5N1 transmission experiments in ferrets at an ASM Biodefense Conference, clarifying several assumptions about the transmissibility of the virus in this animal model.

For the second time in a week I note the passing of an important virologist. Renato Dulbecco, together with David Baltimore and Howard Temin, received the 1975 Nobel Prize in Physiology or Medicine for discoveries about how tumor viruses interact with the genetic material of the cell. Dulbecco also devised ...

The fatality rate for human infections with avian influenza H5N1 is widely quoted at >50%, based on the number of deaths among the fewer than 600 cases confirmed by the World Health Organization. Wang, Parides, and Palese suggest that this number is an overestimate.

Norton Zinder made two important discoveries in the field of virology. While a Ph.D. student with Joshua Lederberg at the University of Wisconsin-Madison he found that viruses of bacteria (bacteriophages) could move genes from one host to another, a process called transduction. Later in his own laboratory at The Rockefeller ...

Peter Palese and Taia Wang have written a compelling article that uses scientific facts to address the controversy over publication of research involving transmission of avian influenza H5N1 in ferrets. In response to calls in the media to destroy the viruses, curtail the research, and protect the public from frightening ...

A group of seventeen virologists is asking a U.S. government biosecurity advisory board to reconsider its controversial recommendation that two research teams omit key details from papers in press at Science and Nature. They note that the H5N1 fatality rate quoted widely is incorrect, and that the ferret-passaged virus ...

The finding of viral nucleic acid sequences in illegally imported wildlife products has attracted the attention of the New York Times, which published an article entitled From the jungle to J.F.K., viruses cross borders in monkey meat.

Renowned influenza virologist Peter Palese has penned an opinion column for the science journal Nature in which he uses his experience in reconstructing the 1918 pandemic influenza virus strain to question the censoring of H5N1 results by the National Science Advisory Board for Biosecurity (NSABB)

In a lead editorial the New York Times argues why the recent research on avian influenza H5N1 should not be published, and why it constitutes a threat to humanity. They get all of the facts wrong, and base their opinions on incorrect science. Among the problems: they flatly state that ...

Why is there such widespread fear of avian H5N1 influenza virus?
Why did Paul Keim, chair of the National Science Advisory Board for Biosecurity (NSABB) say “I can’t think of another pathogenic organism that is as scary as this one”. What lead Donald McNeil, writing about H5N1 in the New ...

A paper that reported finding retroviral sequences in blood from patients with chronic fatigue syndrome (CFS) has been retracted by the authors. Just four days ago the 2009 Science report of Lombardi and colleagues was editorially retracted. As 2011 comes to an end, so does the hypothesis that retroviruses are ...

The virologists who carried out the contentious experiments on influenza H5N1 transmission in ferrets have agreed to remove certain details from their manuscript, according to ScienceInsider. This is a bad day for virology, and for science in general. The decision by the NSABB sets a precedent for censoring future experimental ...

The mantle of world’s biggest virus has passed from Mimivirus to Megavirus. But in this case, size doesn’t matter. It’s the genes that these viruses share and do not share that make this story important.

The genome nucleotide sequence has been determined of the bacterium GFAJ-1, which has been suggested to survive in high levels of arsenic and in fact incorporate arsenic into macromolecules. The sequence does not address the controversy over whether the bacterium can utilize arsenic. I suppose that it is so easy ...

A laboratory in the Netherlands has identified a lethal influenza H5N1 virus strain that is transmitted among ferrets. These findings are under review by the National Science Advisory Board for Biosecurity (NSABB) to ensure that they do not constitute a threat to human health. Meanwhile both the popular and scientific ...

According to the New York Times (Why Science Majors Change Their Minds), the decline in the number of science majors in the United States has come about in part because the subject matter is too difficult. If this explanation is true, then we have not properly prepared these students in ...

David Tuller, health journalist and Berkeley faculty member, has written a piece on the CDC's handling of CFS. His account draws from interviews, a close reading of a fraction of the 4608 epidemiologic studies that pop up on a PubMed search for “chronic fatigue syndrome,” and a review of many ...

I hear from many readers that they routinely get the flu vaccine every year, yet they often contract the disease. I usually tell them that the vaccine is not perfect: it doesn’t protect everyone who gets it. Now we have the numbers to back up this statement, and they are ...

In my recent keynote address to the Brazilian Virology Society entitled The World of Viruses, I presented my list of ten seminal virologists. The idea to include such a discussion came from David Baltimore, who sent me his list. Our lists had some but not all individuals in common. What ...

I was honored to present the Keynote Address at the XXII meeting of the Brazilian Virology Society on 23 October 2011. In my talk entitled The World of Viruses, given to an audience of 640 virologists, I shared my enthusiasm for these amazing microbes by discussing ten seminal virologists and ...

There is an excellent question in the comments to “Are all virus particles infectious?“: if the particle-to-PFU ratio for a virus stock is 10,000:1, and I infect 1,000,000 cells with 10,000 particles, how many plaques would I expect to observe? Answering this question provides insight into the particle-to-PFU ratio of ...

Recent research has suggested a new method of flu prevention and treatment: the administration of granulocyte macrophage-colony stimulating factor (GM-CSF) to the lungs of mice significantly reduced flu symptoms and prevented mortality after a lethal dose of influenza virus. GM-CSF helps the body defend against the virus by boosting the ...

Judy A. Mikovits, the embattled scientist who led the research team that found a possible link between the retrovirus XMRV and patients with chronic fatigue syndrome, has been terminated from her job as director of research at the Whittemore Peterson Institute for Neuro-Immune Disease in Reno, Nev.

Robert A. Weisberg was a Scientist Emeritus at NCI until the time of his death on 1 September 2011. Previously he was Chief of Microbial Genetics at NICHHD, a position he retired from in 2008. He was a pioneer in the study of the bacteriophage lambda. His research lead to ...

Whether or not the retrovirus XMRV is a human pathogen has been debated since the virus was first described in 2006. The answer is now clear: the results of Blood XMRV Scientific Research Group, along with a partial retraction of the 2009 Science paper describing identification of the retrovirus in ...

The bacteria in our intestines outnumber by tenfold the 100 trillion cells that comprise the human body. This gut microbiota has many beneficial functions, including the production of vitamins and hormones, fermentation, regulation of gut development, and shaping intestinal immune responses. They also play a role in pathological conditions such ...

I just returned from a 17-day, 3,000 km road trip with my family in Europe. When I travel I’m always on the lookout for virus-related information and I found some at the Deutsches Museum in Munich, Germany. This museum showcases science and technology – it has over 100,000 objects illustrating ...

Professor Vincent Racaniello will be a guest today, Thursday 28 July, on Dr. Kiki's Science Hour. Tune in to live.twit.tv at 7:00 PM EDT and listen to Dr. Kirsten Sanford discuss viruses with the host of 'This Week in Virology', 'This Week in Parasitism', and 'This Week in Microbiology'.

Last week I attended the 30th annual meeting of the American Society for Virology in Minneapolis, Minnesota. During the morning symposia, which consist of formal 35-minute talks, I decided to post ongoing summaries of each talk on Twitter, a process known as ‘live tweeting’ or ‘live blogging’. Some individuals were ...

Yesterday I terminated the last remaining mice in my small colony, including the line of poliovirus receptor transgenic mice that we established here in 1990. Remarkably, I had never written about this animal model for poliomyelitis which has played an important role in the work done in my laboratory.

The expression “Happy as a Clam” comes with new meaning as hepatitis A virus has been detected in clams, mussels, and oysters in markets for human consumption. As bivalve shellfish are excellent bio-accumulators of contaminants and chemicals, it is no surprise that they also harbor waterborne viruses such as hepatitis ...

Analysis of poliovirus recovered from the stool of a patient with fatal poliomyelitis revealed that she had been infected with the virus 12 years earlier, probably when one of her children received the oral poliovirus vaccine. This case has the longest known incubation period for vaccine-derived poliomyelitis, and highlights our ...

The retrovirus XMRV arose during passage of a human prostate tumor in nude mice. The genomes of these mice contain two different proviral DNAs related to XMRV, pre-XMRV-1 and pre-XMRV-2, that recombined to produce XMRV that has been isolated from humans. Two other prostate cancer cell lines also contain mouse ...

Photograph of a poster issued by the Chinese government in the late 1970s depicting the spread of schistosomes to humans from snails as a consequence of agricultural practices. These posters have been in the office of Dickson Despommier since the 1970s.

Photograph of a poster issued by the Chinese government in the late 1970s depicting the spread of hookworm to humans by the use of human feces as fertilizer. A prevention method is also illustrated - wearing shoes. These posters have been in the office of Dickson Despommier since the 1970s.

A team at MIT has been able to use a genetically engineered virus to help build carbon nanotubes, microscopic cylinders that are integral in constructing high-efficiency solar cells. These nanotubes had proven difficult to construct due to their small size, and traditional techniques were doing a poor job. However, a ...

The novel human retrovirus XMRV has been associated with prostate cancer and chronic fatigue syndrome. The nucleotide sequence of XMRV isolated from humans indicates that the virus is nearly identical with XMRV produced from a human prostate tumor cell line called 22Rv1. This cell line was derived by passage of ...

Rich Condit found an article highly critical of the original Wakefield study (claiming a link between MMR vaccine and autism) which was published in the same issue of Lancet. He asked the publisher, Elsevier, to open up the article to non-subscribers so he could recommend it as a pick of ...

Contemporary human viruses most likely originated by cross-species transmission from non-human animals. Examples include HIV-1, which crossed from chimpanzees to humans, and SARS coronavirus, which originated in bats. Since the 1989 discovery of hepatitis C virus (classified as a hepacivirus in the family Flaviviridae) the origin of the virus been ...

The World Health Organization has decided not to recommend destruction of the remaining stocks of smallpox virus. This debate has been ongoing since 1980, when the disease was declared eradicated. WHO has indicated that no new experiments on smallpox virus will be permitted, only conclusion of ongoing studies. For the ...

In 1983, identical twins boys simultaneously received a contaminated blood transfusion immediately after birth, and were subsequently diagnosed with HIV-1. Years later, one of the twins is faring very well and has a near normal immune system, while the other is in poor health and has experienced many complications. How ...

Since the first association of the retrovirus XMRV with chronic fatigue syndrome in 2009 in the US, subsequent studies have failed to detect evidence of infection in patients from the US, Europe, and China. These studies were potentially compromised by a number of factors, such as differences in patient characterization, ...

Professor Dickson Despommier, co-host of TWiV and TWiP, and well known for his ideas about vertical farming, taught parasitology to medical, dental, and nursing students at Columbia University’s College of Physicians & Surgeons for 38 years. Below are videocasts of the six lectures from the final version of his course, ...

Amyotrophic lateral sclerosis (ALS), also known as motor neuron disease or Lou Gehrig’s disease, is a fatal disorder of unknown etiology. The disease involves degeneration of motor neurons, leading to paralysis, respiratory failure, and death within five years. A viral etiology for ALS has been suggested but never proven. Retroviruses ...

What would you conclude if you read the following headlines: Man sexually transmits insect-borne disease to wife (Fox News); Zika virus: First insect borne STD? (HuffPo); Scientist gives insect-borne disease to wife during sex (New York Magazine), and A scientist contracts a mosquito-borne virus and gives it to his wife ...

Glenn Rall, a virologist at Fox Chase Cancer Center, sent me the following note:
Baruch S. Blumberg, Nobel Laureate in 1976 for discovery of Hepatitis B (and the eventual development of the vaccine, which probably has saved hundreds of thousands of lives since its introduction), died this past Tuesday (4/5/11).

Last week we discussed the second known virophage, but we didn’t have any explanation of why such viruses might evolve. This week we have the discovery of a third virophage, hints of many more, and a hypothesis for what they might be doing in the global ecosystem.

Myra McClure, Professor in the Division of Infection and Immunity, University College of London, U.K., has focused on retroviruses for much of her research career. I discussed the potential role of the retrovirus XMRV in prostate cancer and chronic fatigue syndrome with Dr. McClure during ICAAC Boston 2010, as part ...

After the eradication of smallpox in 1980, the World Health Organization called for destruction of known remaining stocks of the virus. The United States and Russia, which hold the known stocks of smallpox virus, have not destroyed their stocks. During TWiV #124, I was surprised to learn that the remaining ...

The first detailed study of infection of nonhuman primates with the retrovirus XMRV reveals that the virus establishes a persistent infection characterized by infection of multiple tissues. Viremia (virus in the blood) is low and transient, with proviral DNA detectable in blood lymphocytes. The results show that the Rhesus macaque ...

A type of human encephalitis – an infection of the brain – has been known to affect the indigenous people living in the Sakha Republic of Russia since the mid-1800s. The available clinical and epidemiological evidence suggests that the disease is caused by a pathogen, but proving this has been ...

Frederick Hayden, Professor of Medicine and Pathology, University of Virginia School of Medicine, U.K., has focused on the use of antiviral agents to prevent and treat respiratory viral infections. I discussed the use of antiviral drugs to treat influenza with Dr. Hayden during ICAAC Boston 2010, as part of TWiV ...

My virology course at Columbia University, Biology W3310, has begun. This course, which I taught for the first time in 2009, is aimed at advanced undergraduates and will be taught at the Morningside Campus of Columbia University. Read on to learn how to access all the course materials, including videocasts ...

Chris Upton, a contributor to the virology toolbox, has raised an important point about multiplicity of infection:
Perhaps this is a place to bring up particle to pfu ratio? The above is great for when talking about phage, for example, when the ratio approaches 1. But with something like polio when ...

Multiplicity of infection (MOI) is a frequently used term in virology which refers to the number of virions that are added per cell during infection. If one million virions are added to one million cells, the MOI is one. If ten million virions are added, the MOI is ten. Add ...

Derek Smith, Professor of Infectious Disease Informatics, University of Cambridge, U.K., has developed a method for visualizing antigenic evolution by creating two-dimensional maps in a process called antigenic cartography. These maps are made with data that provide information on the antigenic properties of the pathogen. In the case of influenza ...

New York Times article by David Tuller, a journalism professor at Berkeley, on chronic fatigue syndrome and the retrovirus XMRV. The main focus of the article are four papers published in the journal Retrovirology at the end of 2010 which pointed to contamination as a potential issue for those attempting ...

A strong argument that the novel human retrovirus XMRV is not a laboratory contaminant is the the finding that viral DNA is integrated in chromosomal DNA of prostate tumors. Why does this result constitute such strong proof of viral infection?
Establishment of an integrated copy of the viral genome – the ...

On my recent trip to record TWiV #111 at Florida Gulf Coast University, I visited Rich Condit in Gainesville. There he told me a story about how the bacteriophage T7 polymerase/promoter system was developed. It’s an interesting tale that demonstrates how important scientific advances often have convoluted roots.
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Yesterday the Chicago Tribune published my reaction to the four papers on the retrovirus XMRV published this week in the journal Retrovirology. I was quoted as saying ”These four papers are probably the beginning of the end of XMRV and CFS”. I wish to retract this statement and explain my ...

Since the first observations that the human retrovirus XMRV is associated with prostate cancer and chronic fatigue syndrome (CFS), new studies have been carried out to determine the role of the virus in these diseases. The results have been conflicting: XMRV (and related retroviruses) have been found in some patients, ...

During the replication of retroviruses, a double-stranded DNA copy of the viral RNA genome is synthesized by reverse transcription and integrated into the genomes of the infected cell. When retroviral DNA is integrated into the DNA of germ line cells, it is passed on to future generations in Mendelian fashion ...

Influenza researcher Peter Palese visited yesterday and spoke about “Pandemic influenza: Past and Future”. A key part of his talk was a review of his efforts to produce a universal influenza vaccine which protects against all strains. He used the following graph to make the point that when influenza pandemic ...

A salt-loving (halophilic) bacterium which can grow in medium containing arsenic instead of phosphorus has been selected from the microbial community of Mono Lake in California. Arsenic (As) is a chemical analog of phosphorus and is usually toxic because it can enter metabolic pathways in the place of phosphorus. It ...

Australian virologist Frank Fenner, MD was born in Ballarat, Victoria in 1914. He earned a Doctor of Medicine in 1942 at the University of Adelaide, and from 1940 – 1946 he worked on the malaria parasite in Egypt and Papua New Guinea as an officer in the Australian Army Medical ...

As a college biology major during the 1970s I was taught that cells in which the genetic material is separated from the cytoplasm by a nuclear membrane – such as those of animals, fungi, plants, and protists – are called eukaryotes. In contrast, the DNA of bacteria is not bounded ...

Social media consists of Internet technologies that allow users to create and share content, and to foster dialogues among other users. Examples include software applications for communication (blogging, social networking, discussion forums), collaboration (wikis, social bookmarking), and multimedia (sharing photographs, video, and livecasting). In the world of science, social media ...

The need to re-formulate the influenza virus vaccine in response to viral antigenic drift and shift makes for complex logistics of vaccine production and administration. Surveillance programs must be conducted each year to identify strains that are likely to predominate and cause disease. Wouldn’t it be simpler if a single ...

Many virological techniques are based on the specificity of the antibody-antigen reaction. Examples in our virology toolbox include western blot analysis and ELISA. While very useful, these methods cannot be used to visualize viral proteins in infected cells or tissues. To do that we must turn to immunostaining.

All known virus particles can be placed into one of two general categories: enveloped or non-enveloped. Viruses that fall into the former category are characterized by a lipid membrane derived from the host cell, and one or more nuclecapsid proteins that interact with the viral genome. A virus that infects ...

The new human retrovirus XMRV, first detected in malignant prostate tissue, was subsequently identified in a high percentage of patients with chronic fatigue syndrome (CFS). The virus was not detected in four independent studies of CFS patients in Europe or the United States. The results of a second American study, ...

How XMRV, the new human retrovirus associated with prostate cancer and chronic fatigue syndrome, might be transmitted among humans is unknown. The finding that the virus can be detected in prostate cancer cells, and in prostatic secretions of men with prostate cancer suggests that it could be sexually transmitted. To ...

Dotplots are an extremely useful way of visualizing comparisons of small and large DNA sequences (as well as protein sequences), providing insight into the degree of similarity, deletions, insertions and direct and indirect repeats. In a dotplot, each nucleotide, or small window of nucleotides, of one sequence is compared with ...

Chanock received his MD in 1947 from the University of Chicago, and after clinical training in pediatrics (note the bowtie), joined Albert Sabin at the University of Cincinnati where he studied arthropod-borne viruses. After a stint in the US Army, he rejoined Sabin’s laboratory in 1954 as an independent investigator. ...

First, you may be asking yourself – Why viral bioinformatics? Good question! Although it’s true that much in the world of bioinformatics can be applied to all manner of protein and DNA sequences, there are a number of resources that are specific for viruses and there are a number of ...

The illustration at left depicts a virion – the infectious particle that is designed for transmission of the nucleic acid genome among hosts or host cells. A virion is not the same as a virus. I define virus as a distinct biological entity with five distinct characteristics. Others believe that ...

Global fish farming may be the solution to the impending collapse of the commercial fishing industry, but penned fish are susceptible to infectious diseases. Infection with salmon infectious anemia virus, an orthomyxovirus, lead Wal-Mart to stop buying farmed salmon from Chile, the world’s second largest producer of the fish. As ...

Readers of virology blog often request explanations of specific experimental techniques. Methods such as complement fixation, deep sequencing, ELISA, PCR and many others are frequently mentioned on this blog without discussion. To do so would interrupt the scientific discourse and make for lengthly posts. To remedy this shortcoming, I have ...

The findings by the NIH and FDA that XMRV is associated with chronic fatigue syndrome has been accepted for publication by the Proceedings of the National Academy of Sciences (PNAS). Release of the article has been blocked by PNAS due to work carried out by the US Centers for Disease ...

The influenza virus neuraminidase (NA) protein is required for virus release from the cell, a property exploited by the antiviral drugs oseltamivir (Tamiflu) and zanamavir (Relenza). During clinical testing of oseltamivir in 2001, some individuals shed drug-resistant viruses with an amino acid change from histidine to tyrosine (H274Y) in NA. ...

When infection with hepatitis C virus goes from acute to chronic, severe liver disease may occur which requires organ transplantation. Nearly 200 million people are chronically infected with HCV, necessitating approaches to preventing and treating infections. No HCV vaccine is available, and current antiviral therapy consists of administration of interferon ...

Robert H. Silverman, one of the authors on the study implicating the new human retrovirus XMRV as an etiologic agent of chronic fatigue syndrome, has written an excellent review article on the current status of research on the virus. The article is behind a paywall at Nature Reviews Urology, so ...

A serious shortcoming of current influenza virus vaccines is the need to reformulate them every year or two as the virus undergoes antigenic drift. Many virologists have been captivated by the idea of a more universal vaccine that would endure longer, perhaps a decade or more. The identification of a ...

I joined Marc Pelletier on episode 60 of Futures in Biotech for a conversation with Dave Brodbeck, George Farr, and Andre Nantel. We talked about primate face recognition, discovery of a new antiviral compound to treat hepatitis C virus infection, changing the length of a codon from three to four ...

An important question about the retrovirus XMRV, which has been implicated in prostate cancer and chronic fatigue syndrome, is where the virus replicates in humans. Such information would provide clues about how infection might be transmitted. To date the virus has been detected in malignant prostate cells and in the ...

Bovine viral diarrhea virus is an economically important animal pathogen that may cause a fatal gastrointestinal disease in beef and dairy herds. Infection of a fetus with this virus during the first trimester leads to the birth of animals that are persistently infected for life. Some animals remain healthy, while ...

The US Food and Drug Administration recently recommended that administration of Glaxo SmithKline’s Rotarix vaccine, which protects against rotavirus infection, be suspended after an independent research group found that the vaccine contains DNA of porcine circovirus type 1. Now the FDA reports finding circovirus DNA in the rotavirus vaccine made ...

It has been estimated that approximately one hundred trillion bacteria colonize the human intestine. That’s about ten times the number of cells that constitute the entire human body. These bacteria are believed to have a mutualistic symbiotic relationship with their hosts. What is known about the viral communities that inhabit ...

Viruses can be transmitted to completely new host species that they have not previously infected. Usually host defenses stop the infection before any replication and adaptation can take place. On rare occasions, a novel population of viruses arises in the new host. These interspecies infections can sometimes be deduced by ...

All mammalian genomes contain genes encoding Apobec proteins. Several members of this protein family (the name stands for apolipoprotein B mRNA editing complex) are induced by interferon and are intrinsic antiretroviral proteins. Apobec proteins inhibit the replication of XMRV, a new human retrovirus associated with prostate cancer and chronic fatigue ...

Deep sequencing – which identified a viral contaminant of the rotavirus vaccine Rotarix - could have revealed the presence of simian virus 40 (SV40) in the poliovirus vaccine, had the technique been available in the 1950s. Exposure of over 100 million Americans to SV40, and many more worldwide, could have ...

The contamination of the rotavirus vaccine Rotarix with porcine circovirus 1 DNA was revealed by deep sequencing. The same technique was also used to demonstrate that oral poliovirus vaccine does not contain viruses that can cause poliomyelitis.

Xenotropic murine leukemia virus related virus (XMRV) has been implicated in prostate cancer and chronic fatigue syndrome (CFS). Because XMRV is a retrovirus, it might be susceptible to antiviral drugs that are licensed for the treatment of AIDS. AZT (azidothymidine) was previously found to block XMRV replication. A screen of ...

The recent discovery of contaminating porcine circovirus 1 DNA in Rotarix underscores the power of deep sequencing to ensure the purity of viral vaccines. The price of deep sequencing is now low enough that it is possible to use this technology to examine not just viral vaccines, but any biological ...

Use of the rotavirus vaccine Rotarix in the US has been temporarily suspended because the vaccine was found to be contaminated with porcine circovirus 1 DNA. The discovery was made in the laboratory of Dr. Eric Delwart, who has provided insight into what was found in Rotarix, and why he ...

The US Food and Drug Administration does not want Rotarix, the rotavirus vaccine, to be used because it contains porcine circovirus 1 DNA. If complete copies of the circovirus genome were present, would they constitute a potential threat to recipients? Put another way, is circovirus DNA infectious?

The US Food and Drug Administration has recommended that administration of the Rotarix vaccine, which protects against rotavirus infection, be suspended. This action comes after an independent research group found that the vaccine contains DNA of porcine circovirus type 1.

Last year a mutation in the HA gene of the 2009 H1N1 influenza virus was identified in isolates from patients with severe disease. At the time I concluded that the emergence of this change was not a concern. Recently the Norwegian Institute of Public Health reported that the mutation, which ...

Contagion is the name of a new action-thriller movie about a global outbreak of a deadly viral disease. Slated to be released in 2011, it is directed by Steven Soderbergh and stars Matt Damon, Kate Winslet, Jude Law, Marion Cotillard, Gwyneth Paltrow, and Lawrence Fishburne. That’s certainly an outstanding crew, ...

On a recent episode of TWiV, we posed the question, 'Can computer viruses evolve'? and asked listeners to weigh in. The author of the blog nostacktrace spent some time thinking about this issue and concludes that the evolution of real computer programs doesn't really work. Software instructions are very brittle. ...

The second RNA segment of some influenza virus strains encodes a protein called PB1-F2 that might contribute to virulence. Speaking about the 2009 pandemic H1N1 strain, Peter Palese noted that “If this virulence marker is necessary for an influenza virus to become highly pathogenic in humans or in chickens, then ...

The World Health Organization and the US Food & Drug Administration have decided on the composition of the influenza virus vaccine that will be used during the 2010-2011 season in the northern hemisphere. The trivalent preparation will contain the following influenza virus strains: A/California/7/2009 (H1N1); A/Perth/16/2009 (H3N2); and B/Brisbane/60/2008. The ...

No matter what advanced method is used to develop and produce vaccines, their efficacy is limited by old technology – the refrigerator. All viral vaccines must either be stored frozen, or kept at low temperatures. If they are not properly stored, they lose potency and do not confer protection against ...

The suggestion that the retrovirus XMRV is the etiologic agent of chronic fatigue syndrome (CFS) arose from a study in which the virus was found in 68 of 101 US patients. The virus was not detected in two independent studies of 186 and 170 CFS patients in the United Kingdom. ...

Since electron micrographs first revealed the bullet-shaped morphology of vesicular stomatitis virus (a virus related to rabies virus), understanding the architecture has been elusive. It was known that the RNA genome is wrapped in a helical structure by the viral nucleocapsid (N) protein, but how this structure was encased by ...

Broad spectrum antibiotics are available that act against a wide range of bacteria, including both gram-positive and gram-negative species. In contrast, our antiviral arsenal is exceedingly specific. Nearly all the known antivirals block infection with one or two different viruses. The discovery of a compound that blocks infection with many ...

A new retrovirus, xenotropic murine leukaemia virus-related virus (XMRV), first identified in tumor tissue of individuals with prostate cancer, was subsequently found in 68 of 101 US patients with chronic fatigue syndrome (CFS). XMRV was not detected in blood samples of 186 confirmed CFS patients in the United Kingdom. A ...

Influenza A viruses typically cause severe respiratory disease mainly in the very young or the elderly. The 2009 swine-origin H1N1 virus is unusual because it preferentially infects individuals under 35 years of age. We’ve previously noted that being older is a good defense against 2009 H1N1 influenza virus, in part ...

This year I started a new virology course at Columbia University. The course emphasizes the common reactions that must be completed by all viruses for successful reproduction within a host cell and survival and spread within a host population. The molecular basis of alternative reproductive cycles, the interactions of viruses ...

One of the most important procedures in virology is measuring the virus titer – the concentration of viruses in a sample. A widely used approach for determining the quantity of infectious virus is the plaque assay. In this technique, the spread of progeny viruses released by individually infected cells is ...

Fragments of an abundant protein produced by the prostate form amyloid fibrils that enhance infection of cells by human immunodeficiency virus type 1. These fibrils, called semen-derived enhancer of virus infection (SEVI), have been found to boost infection of prostate cells by the retrovirus XMRV. Is this evidence that XMRV ...

For thousands of years, epidemics of contagious diseases were believed to be caused by the wrath of the gods, configuration of stars, or miasma. The association of specific microorganisms with disease came about as a consequence of the work of the German physician Robert Koch. He formulated a set of ...

Tomorrow is the start of my new virology course at Columbia University. The course, Biology W3310, is aimed at advanced undergraduates and will be taught at the Morningside Campus of Columbia University.

The chromosomal DNA of several mammals has been found to contain sequences related to the nucleoprotein (N) gene of bornaviruses, enveloped viruses with a negative-strand RNA genome. I am amazed by this finding. How did bornaviral DNA get in our chromosomes, and what is it doing there?

A new retrovirus, xenotropic murine leukaemia virus-related virus (XMRV), first identified in tumor tissue of individuals with prostate cancer, was subsequently found in 68 of 101 US patients with chronic fatigue syndrome (CFS). This observation raised the possibility that XMRV is the etiologic agent of CFS. An important question is ...

Shortly after I wrote about my years of experience with HeLa cells, I was contacted by author Rebecca Skloot. One of her many questions was how I knew that I had produced 800 billion HeLa cells in my laboratory over 26 years. I learned that she was writing a book ...

A new bivalent poliovirus vaccine, consisting of infectious, attenuated type 1 and type 3 strains, has been deployed in Afghanistan. The use of this vaccine was recommended by the Advisory Committee on Poliomyelitis Eradication, the global technical advisory body of the Global Polio Eradication Initiative. Considering the polio experience in ...

Millions of New Yorkers were immunized against smallpox within a few weeks in April 1947. The stimulus for this mass immunization was the importation of smallpox by a businessman who had acquired the disease during his travels. While we are in the middle of a massive influenza immunization campaign, it ...

In the summer of 1989, two papers about viruses were published in high-profile journals. One described the engineering of a recombinant poliovirus bearing on its surface an antigen from HIV-1. The second paper claimed that transgenic mice could be made by adding DNA to sperm before using them to fertilize ...

Simon Owens looks at the impact of bloggers on the dissemination of both good and bad information about swine-origin influenza H1N1. He spoke with Vincent Racaniello of virology blog (virology.ws), Mike Coston of Avian Flu Diary (http://afludiary.blogspot.com/), and Crawford Kilian of H5N1 blog (http://crofsblogs.typepad.com/h5n1/).

Xenotropic murine leukemia virus related virus (XMRV) has been implicated in prostate cancer and chronic fatigue syndrome (CFS). Because XMRV is a retrovirus, it has been suggested that it might be susceptible to some of the many drugs available for treatment of AIDS. Of ten licensed compounds evaluated for activity ...

There is some evidence that viruses are involved in colony collapse disorder, a phenomenon in which worker bees disappear. This condition is receiving a great deal of attention ranging from basic scientific research (summarized on TWiV 46) to a PBS episode to a documentary entitled 'Colony' which says that “The ...

Griffithsin is a sugar-binding protein identified in 2005 as an inhibitor of HIV-1. At the fall meeting of the American Cancer Society it was reported that griffithsin can also block replication of SARS virus and ebolavirus. The protein appears to act by binding carbohydrates on the virion surface and blocking ...

I was given a package of zinc lozenges when I contracted a cold a few weeks ago. That got me interested in the effect of zinc on rhinovirus replication. As a consequence I began a series of experiments to understand the mechanism of inhibition of viral replication by this metal. ...

The Institute of Medicine has been asked to make recommendations about how to protect healthcare workers against swine-origin H1N1 influenza. They have been hearing presentations concerning the effectiveness of facemasks in preventing respiratory infections.